Northern Thames Basin
The Northern Thames Basin is a National Character Area (NCA) as designated by Natural England.[1] It is a diverse area, extending from Hertfordshire in the west to the Essex coast in the east. It is separated from the North Sea and Thames Estuary by a separate NCA, the Greater Thames Estuary. The Northern Thames Basin contains the suburbs of North London, historic towns and cities such as St Albans and Colchester, and new towns such as Welwyn Garden City, Hatfield and Basildon.
The topography is varied, with a wide plateau divided by river valleys. The prominent hills and ridges of the Bagshot Hills are notable to the northwest, and flat land is found in the south. A layer of thick clay, the London Clay, produces heavy, acidic soils. Therefore, much ancient woodland has been retained. Hertfordshire is heavily wooded in some areas as are parts of Essex. Glacial sands and gravels have resulted in nutrient-poor which support small areas of remnant lowland heathlands. There are alluvial deposits which produce well drained and fertile soils. The underlying chalk beds are a main source of recharge for the principal London Basin Chalk aquifer. There are broad valleys containing the major rivers Ver, Colne and Lea, and slightly steeper valleys containing other rivers.
Principal summits
Although a low-lying area, the clay gives rise to a number of separate low hills. The following hills within the NCA have at least 30 metres of topographic prominence:[2]
| Hill | Elevation | Prominence | Grid reference |
|---|---|---|---|
| Bushey Heath | 153.4 m (503 ft) | 80 m | TQ151939 |
| Deacons Hill | 147.6 m (485 ft) | 30.6 m | TQ183949 |
| Highwood Hill | 143.9 m (472 ft) | 31.2 m | TQ218941 |
| Sandy Lane | 135 m (443 ft) | 62 m | TQ105919 |
| Shenley Hill | 134 m (440 ft) | 32 m | TL190006 |
| Burnham Green | 126.4 m (415 ft) | 32 m | TL264165 |
| Harrow on the Hill | 124 m (407 ft) | 71 m | TQ153874 |
| Brentwood Park | 120.9 m (397 ft) | 57 m | TQ590913 |
| Langdon Hill | 118 m (387 ft) | 81 m | TQ679865 |
| Epping Forest | 117.2 m (385 ft) | 38 m | TL435003 |
| Danbury Ring | 111 m (364 ft) | 63 m | TL779051 |
| Havering atte Bower | 107 m (351 ft) | 38 m | TQ516930 |
| Lambourne Hill | 102 m (335 ft) | 39 m | TQ478951 |
| Bell Hill | 98.9 m (324 ft) | 33.8 m | TQ674939 |
| Wakemans Hill | 92 m (302 ft) | 40 m | TQ207889 |
| Criers Wood | 89 m (292 ft) | 50 m | TL857132 |
| Barn Hill | 86 m (282 ft) | 32 m | TQ193873 |
| Horsenden Hill | 84.9 m (279 ft) | 32 m | TQ161843 |
| Thundersley Hill | 84.5 m (277 ft) | 66 m | TQ790880 |
| Wembley Hill | 72 m (236 ft) | 33 m | TQ186855 |
| Hanger Hill | 65 m (213 ft) | 33 m | TQ187820 |
| Stamfords Hill | 52.8 m (173 ft) | 33 m | TQ892986 |
| Sandy Lane Pit | 47.2 m (155 ft) | 30.1 m | TQ557809 |
References
- ↑ "Northern Thames Basin". National Character Area Profiles. Retrieved 2026-04-12.
- ↑ https://www.hill-bagging.co.uk/